One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By referring to the USDA zone info for Northbrook it's possible to determine when it's the best time to plant phlox.

Planting Calendar for Phlox

Frost tolerance for phlox:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Phlox are one of those plants that can tolerate a little bit of cold weather which tells us that you can plant them earlier than other plants that might not handle the cold.

The earliest that you can plant phlox in Northbrook is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant phlox and expect a good harvest is probably September. Any later than that and your phlox may not have a chance to fully mature. You can get started a few weeks earlier by starting your phlox indoors.

Last Frost Date

The average date of last frost is April 15 in Northbrook. In the coldest months of winter you should expect an average low temperature of -15°F.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Northbrook and it can change quite a bit from year to year. Since half of the time in Northbrook last frost occurs after April 15 be ready to cover your phlox if you have one of those late frosts.

USDA Zone Info for Northbrook

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Northbrook

You may be interested in your other planting guides for Northbrook.